Eock brill



1,627,744 E. B. LEAR 'ROCK DRILL May 1, 19279 Filed Lee. 1 1 ,925

IN VEN TOR.

Patented ll/lay ill, i927,

EAR'L B. LEAR, 0F PHILLITSBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL-RAND COMPANY, 035 JERSEY CITY, NEW' JERSEY, A CORPORATION OF NEW JERSEY.

R0 CK DRILL.

Application filed December 17, 1925.

This invention relates to fluid actuated rock drills, but more particularly to an improved valve for distributing pressure fluid to the reciprocatory element of rock drills.

One object of the invention is to protect the valve chest against wear by eliminating contact between said valve and the valve chest.

Uther objects are to improve generally in valves of the oscillatory type and to enable the valve and the associated parts to be quickl assembled or disassembled.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention consists of the combinations of elements, features of construction,

and arrangement of parts havina the general mode of operation substantially as hereinafter described and more particularly point-- ed out in the appended claims and illustrated in the accompanying drawings, in which Figure 1 is an elevation in section of a portion of a rock drill constructed in ac cordance with the practice of the lIl VGIllllOIl showing the valve in position for admitting air to the rearward end of the cylinder to drive the piston forwardly,

Figure 2 is a view similar to Figure 1 showing the valve in position to admit air to the front end of the cylinder for impelling the piston rearwardly,

Figure 3 is a transverse view in section taken through Figure 1 on the line 3-3 looking in the direction of the arrows, and

Figure 4- is an elevation in section of a modified form of valve and valve seat.

Referring to the drawings, the invention is shown embodied in a rock drill having a cylinder A provided with a free exhaust port B. catory hammer piston 0 having a forward fluted extension or nose D adapted to deliver blows on a drill steel (not shown). A suitable closure for the front end of the cylinder A is in this instance provided in the form a of a front cylinder washer E bored to receive slid-ably the nose D of the piston C. A back cylinder washer F inserted in the rearward end of the cylinder A forms a closure for the rearward end of said cylinder and in this instance also serves as an abutment for one end of a rotation ratchet G which is centralized by the cylinder and at its other end projects into a back head H.

The parts comprising the casing of the rock drill, namely, the front cylinder washer Within the cylinder A is a recipro- Serial No. 76,043.

E, the cylinder A, the rotation ratchet G and the back head H are in this instance held in through suitable lugs K formed on opposite sides of the casing parts.

Usually in drills of this type suitable rotation mechanism is provided for rotating the drill steel in the drill. hole. Accordingly, in this instance, a fluted rifle bar L, ektending through the back cylinder washer F, engages the piston C in the usual manner and carries near its rearward end a ratchet head O. Suitable pawl devices 1, which mayv be of any well known type, are carried by the ratchet head 0 to cooperate with the rotation ratchet G for holding the rifle bar stationary during one ofthe strokes of the piston C, preferably during its rearward stroke, and adapted to release the rotation ratchet duringthe forward stroke of the piston. v

In the present instance, a valve chest Q, is shown formed integrally with the cylinder A and has a cylindrical bore R in constant comn'iunication with the pressure liuid supply connection S through passages T and U. The cylindrical bore R in this instance has an end wall V integral with the valve chest Q and is open only at one end and threaded as at W to receive a correspondingly threaded plug X whereby the open end of the bore ll may be sealed.

li ithin the bore R is arranged a cyliir drical valve block Y forming a seat and having in its side a concave recess Z preferably of a width to span the passages T and U and extending throughout the length of said block. Jr slot 7) preferably having parallel walls .0 and (Z .is formed longitudinallv through the block Y to communicate at one end with the concave recess Z and opening at its other end in a cylindrical bore formed longitudinally through the block at the inner end of the slot 5.

Arranged to oscillate between the parallel walls 0 and (Z is an oscillatory distributing plate valve f having a wing g. A trunnion 7L integral with the wing g, is adapted to rotate in the bore 6 to serve as a pivot for the valv The sides of th wing g are in this instance tapered so that the widest point of the wing is near the juncture of said wing and the trunnion ii. In order to insure a quick and positive action of the valve, the wing g of the valve is made of a width to enable its outer or free end to extend into the recess Z so that a portion of the opposed side faces of the wing g are constantly exposed to live pressure fluid tending to throw the valve from one limiting position to the other. The degree of angularity or taper of the wing 9 determines the travel of the valve between the parallel walls 0 and d.

Leading in opposite directions from the slot 1) in the valve seat Y are transverse suplply passages j and 71: communicating witi passages 0 and 1) formed through the valve chest Q and leading to the rearward and front ends of the cylinder A respectively. The valve block Y may be held against rotation with respect to the bore R in any suitable manner, a convenient form being shown in the drawings in which after the valve block Y is inserted in the bore R, a tap is former on the line of contact between said valve block and said bore for the reception of a headless screw g. If desired, a drilled hole may be formed instead of the tap and a plain pin may be substituted for the screw As stated, the screw 9 merely serves to hold the valve block Y against rotation, and the valve block and the valve are held against endwise movement in the bore R by the plug X.

In the operation of the rock drill, with the valve 7 in its forward position and the piston C in its rearward position as illustrated in Figure 1, pressure fluid entering the slot 1) will pass through the passages j and 0 to the rearward end of the cylinder A and will impel the piston forwardly to deliver its blow against the drill steel. As the piston C proceeds on its forward stroke, the free exhaust ort B will be covered thereb and from t ence a certain compres sion 0. the atmosheric air entrapped in the front end of the cylinder will take place. The air thus compressed will act against the valve and will tend to tip or rock said valve about its pivot. After the piston G has overrun the exhaust port B, the air utilized for impelling the pistonv forwardly will be exhausted to the atmosphere. WVith the rearwardend of the cylinder A open to the atmosphere, there will be a considerable drop in pressure rearwardly of the valve f so that the live pressure fluid acting against the forward face of the valve, outside of the limits of the passage 70, augmented by the compressed atmospheric air acting against the valve through the passage 1) and by the suction created by the live pressure fluid passing over the end of the valve will rock the valve rearwardly to the position shown in Figure 2. In this position of the valve, pressure fluid will be admitted through the passa es is and p to the front end of the cylinder A and drive the iston C rearwardly. After the piston overruns the exhaust port B during the rearward stroke of the piston, the front end of the cylinder will be opened to atmosphere, thus causing a drop in pressure forward- 1y of the valve. The valve will then again be rocked forwardly to the position shown in Figure 1. The valve is preferably slightly shorter from its pivotal point to the end of the Wing 9 than the distance from the pivotal point of the valve to the nearest point in the wall of the bore B when the valve is in its limiting positions, so that a slight: clearance will exist between said valve and the wall of the bore R. In this way contact between the valve and the valve chest will be at all times prevented, thus protecting the valve chest against wear.

In the modification shown in Figure 4:, a cylindrical valve block 1' is shown having a tapered slot 8. The slot 8 in this instance has converging walls t and a which are connected at their innermost ends by a curved wall '0.

Within the slot .9 is arranged a valve w which in this instance is formed of a single piece and is bent to have an arcuate portion w and wings y and e for controlling the passages j and 10 respectively. The wings y and .2, like the walls 29 and u, are alsoformed at an angle with respect to each other. The angularity of the wings is slightly less than the angularity of the walls so that when the valve is in one of its limiting positions, an angular space will exist between the opposite wing and the adjacent wall to allow the free passage of pressure fluid from the inlet connection S into the passage 1:.

In this modification, the wings y and 2 are also of a length to prevent contact with the wall of the bore R. In order to insure perfect seating of the valve in on the curved wall 4), a rod or pin 2 is held on the inner surface of the arcuate portion a: in any suitable manner (not shown).

The operation of the valve 10 is as follows: With the valve in the position shown in Figure 4, pressure fluid will pass through the passage to thefront end of the cylinder for driving the piston rearw'ardly. After the front end of the cylinder has been opened to the atmosphere through the port B, the pressure fluid acting against the inner face of the wing z, opposed by the reduced pressure on the opposite face of said wing 2 and by the compression acting against the wing y, will rock the valve forwardly to close the passage is, thus uncovering the passage 9' and admit ting air to the rearward end of the cylinder. After the piston C again overruns the exhaust port'B during'the forward stroke of the piston, pressure fluid acting against the inner face of the wing fl], augmented by the suction of the air, will cause the valve to be rocked rearwardly to the position. shown in Figure 4.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder having afree exhaust port, a valve chest having a cyindrical bore closed at one end, a cylindrical valve block insertable through the open end of the bore, a slot in the valve block in constant communication with live pressure fluid, said slot having parallel Walls, a longitudinal bore at one end of the slot, passages leading from the slot to the ends of the cylinder, a valve oscillating between the parallel Walls for controlling the passages, and a trunnion on one end of the valve to cooperate with the bore for :t'orming a pivot for said valve.

In a fluid actuated rock drill, the combination of a cylinder having a free exhaust port, a valve chest having a cylindrical bore closed at one end, a cylindrical valve block insertable through the open end of the bore, a slot in the valve block in constant communication with live pressure fluid, said slot having parallel Walls, passages leading from the slot to the ends of the cylinder, a valve iscillating between the parallel walls for controlling the passages, a trunnion on one end of the valve to form a pivot for said valve, and a plug in the open end of the bore for sealing said bore and for limiting endwise movement of the valve and the valve block.

3. In a fluid actuated rock drill, the combination of a cylinder having a tree exhaust port, a valve chest having a cylindrical bore closed at one end, a cylindrical valve block insertahle through the open end of the bore, a slot in the valve block in constant comn'iunication with live pressure fluid, said slot having parallel walls, passages leading from the slot to the ends of the cylinder. a valve oscillating between the parallel walls for controlling the passages, zr trunnion integral with the valve and on one end thereof to term a pivot for said valve, a plug in the open end ot the bore for sealing said here and for limiting endwise movement of the valve and the valve block, and means for holding said valve block against rotation with respcct to the bore.

4;. In a fluid actuated rock drill, the combination of a cylinder having a free exhaust. port, a valve chest having a bore, a valve block in the valve chest forming a seat, a longitudinal. slot in the block, a longitudinal bore formed through the block at the inner end of the slot, a recess in the block at the outer end of the slot extending on both sides of the slot, passages leading from the slot to the ends of the cylinder, a valve oscillating in the slot to control the passages, said valve extending With one end into the recess, a portion of the sides of said valve being constantly exposed to pressure fluid tending to throw the valve from one limiting position to another, and a trunnion integral with and at one end of the valve cooperating with the longitudinal bore to form a pivot for the valve.

5. In a fluid actuated rock drill, the combination of a cylinder, a valve chest having a bore closed at one end, a valve block in the valve chest forming a seat and insertable through the open end of the bore, a longitudinal slot in the block, a longitudinal bore in the block at the inner end of the slot, a recess in the side of the block extending on both sides of the slot, transverse passages leading from the slot to the ends of the cylinder, said passages communicating with the slot at a point intermediate the longitudinal bore and the recess, a valve oscillating in the slot to control the passages, said valve extending with its outer end into the recess, a portion of opposite sides of the valve ad jacent the outer end being constantly exposed to pressure fluid tending to throw the valve from one limiting position to another, a trunnion at one end of the valve and integral therewith cooperating with the longitudinal bore to form a pivot for the valve, and a plug in the open end of the bore for sealing said bore and for holding the valve and the valve block against endwise movement.

In testimony whereof I have signed this specification.

EARL B. LEAR. 

